1. Modeling a Growing Season in North Carolina CSI Dublin: The Hunt for the Irish Potato Killer NC DNA DAY Source: http://www.ncdnaday.org/http://www.ncdnaday.org/

2. Introduction It costs $2,000 - $2,500 per acre to produce a crop of potatoes. For a 100 acre field, a grower has invested up to $250,000 by the time his crop is sold. You are a farmer in North Carolina growing sweet potatoes. Youve decided to invest in genetically modified sweet potatoes for this upcoming growing season, in an attempt to increase your harvest and, therefore, your profit. On your handout, there are 15 possible genetic mutations of sweet potatoes. As a farmer, you can afford to choose FIVE modifications for your sweet potatoes.

3. 1. May: Planting There is a late-season frost at the end of the May. If you did not choose the anti-freeze gene, you lose 3 potatoes. Source: http://upload.wikimedia.org/wikipedia/commons/1/18/Creeton_village_in_frost.jpg

4. 2. May: Planting The neighboring lettuce farmer offered to lease your fields to double his early summer lettuce crop. If you bought seed for potatoes for a shorter growing season, you are able to lease him your land and still plant your own potato crop in late June. Add 4 potatoes. Source: http://upload.wikimedia.org/wikipedia/commons/a/a5/Iceberg_lettuce_(IJssla_krop).jpg

5. 3. June-Sept: Growth Its been a bad year for potato farmers. Many farms have been overtaken by caterpillars that eat anything green in sight. If you didnt choose the Bt-modified potatoes, you lose 4 potatoes. Source: http://upload.wikimedia.org/wikipedia/commons/b/ b9/Monarch_catepillar.jpg

6. 4. June-Sept: Growth Its been a very windy year, leading to greater amounts of weed seed dispersal. Weeds are threatening to overtake your farm, and you need to spray Round-up to get the problem under control. If you do not have Round-up ready sweet potatoes, lose 3 potatoes. Source: http://www.uap.com/dynagro/docs/RRcorn2- vs-competitive.gif

7. 5. June-Sept: Growth Your state is experiencing a severe drought. If you bought drought resistance sweet potatoes, add 5 potatoes. Source: http://www.ncdrought.org/

8. 6. June-Sept: Growth Your farm has not been bothered by weeds, but your neighbors has been overrun with weeds. Your neighbor sprayed Round-up and it affected non Round-up ready plants on your farm. Lose 1 potato. Source: http://the-plant- directory.co.uk/images/roundup-pump-and- go.jpg

9. 7. June-Sept: Growth There is a root-knot nematode infestation on your farm. If you did not grow sweet potatoes that were resistant to the parasite, lose 3 potatoes. Source: http://www.ars.usda.gov/ Source: http://www.a vrdc.org/phot os/tomato_di seases/nemat ode_02.jpg

10. 8. June-Sept: Growth There was no sweet potato virus disease this year in North Carolina. If you paid extra for SPVD-resistance potatoes, it didnt pay off. Lose 1 potato. Source: http://www.bspp.org.uk/publications/new- disease-reports/013/2006-16-1.jpg

11. 9. Oct-Jan: Sales and Storage Overseas sales of products with high levels of vitamin C skyrockets. You can double your asking price if you grew sweet potatoes with enhanced levels of vitamin C. This lets you buy more seed for next year. Add 3 potatoes. Source: http://upload.wikimedia.org/wikipedia /commons/1/10/VitaminC.png

12. 10. Oct-Jan: Sales and Storage A new report on the prevention of cancer came out indicating vitamin A as the most important component of a cancer-prevention diet. If you grew sweet potatoes with enhanced levels of B-carotene, the precursor for vitamin A, you can sell your potatoes at an increased profit. Add 4 potatoes. Source: Vitamin A deficiency, 1995 http://www.who.int/vaccines-diseases/en/vitamina/advocacy/ adv05.shtml

13. 11. Oct-Jan: Sales and Storage High protein diets are back in vogue. If you are growing sweet potatoes with increased protein content, add 2 potatoes. Source: http://upload.wikimedia.org/wikipedia/comm ons/9/92/Muscles_anterior.png

14. 12. Oct-Jan: Sales and Storage McDonalds has decided to sell sweet potato fries. As a mass food producer, they are only interested in getting as many fries per potato as possible. If you bred for increased size, add 3 potatoes. Source: http://commons.wikimedia.org/wiki/File:SweetPotato.jpg

15. 13. Oct-Jan: Sales and Storage Martha Stewart has come up with a new sweet potato dish to celebrate Memorial Day. Regular sweet potatoes only last until March. If you grew sweet potatoes that were bred for a longer shelf life, add 2 potatoes. Source: http://www.mobot.org/education/tropicalfeast/images/jsweetpotato.jpg

16. 14. Oct-Jan: Sales and Storage Ben & Jerrys started to make sweet potato ice cream. If you are growing sweet potatoes with enhanced sweetness, they will pay double for your crop. Add 4 potatoes. Source: http://www.flickr.co m/photos/diadesig ns/3688440220/

17. 15. Oct-Jan: Sales and Storage Blue sweet potatoes do not sell. Parents are concerned that the blue color is related to an outbreak of the vaccine-resistant measles. If you are growing blue sweet potatoes, lose 6 potatoes. Source: http://commons.wikimedia.org /wiki/File:Blue_tongue.jpg

18. The End! Count the number of potatoes your group had at the end of the season. Answer the questions in your Analysis and Conclusion section of your lab sheet.